2739. But whence comes the tension in the motor nerves? Obviously only from the cerebral tension. This can originate only in two ways; either through the special organization of the brain, one or the other substance being preponderant, or through the influence of external stimuli.
2740. The encephalic substance becomes more potent than usual, if by rest the cortical substance becomes more arteriose in character. This tension is communicated to all the nerves, sensitive as well as motor, and continues in their interlude with the world and the motor system.
2741. If this encephalic tension is not too potent, it remains only in the brain, without the ability to polarize the nerves also. It then only produces cerebral phenomena, thoughts or dreams.
2742. Dreaming is an encephalic tension excited by the organization, not by the world.
2743. Dreaming is the first step in the liberation of the animal from the vegetable system—it is the first step towards mesmerism.
2744. In a perfect or middling state of health, where the nervous is not very much separated from the tegumentary system, we do not dream.
2745. In a healthy condition an external stimulus would be, consequently, the only cause of waking, did not the long repose bestow a preponderating influence upon the cortical substance. Dreams therefore happen in the morning.
2746. Waking is the intercourse with the world, not with self. If one wakes also from intercourse with self, still the former is synchronous and coexciting.
2747. Thus, if intercourse with the world ceases, sleep originates. If the vegetable intercourse with it also ceases, then death originates. Waking is "consensus" with the world.